it is a sexually transmitted infection or STI
Well stress can cause a lot of health issues. This question is asking how prolonged stress results in the increase in illnesses. Prolonged stress can cause for example; Anxiety Disorder, High Blood Pressure, Mental Disorder, Irritable Bowl Syndrome, Diabetes, and more. I am not sure about choice A because that is not necessarily correct. A stressful life can trigger asthma if you have the condition already so choice B is a possibility. Stress almost always has an effect on the immune system so choice C is the best answer so far. Stress could cause the fight of flight response but I don't think that choice D is what they are looking for.
I would say choice C.
Hope This Helps!
Usually, after a couple of weeks you'll notice slight changes. These changes can include the strengthening of your muscles, gaining more stamina, being able to do more repetitions of an exercise, etc...
